From: Stefan Hajnoczi <stefanha@gmail.com>
To: Max Reitz <mreitz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v4 05/26] qcow2: Use unsigned addend for update_refcount()
Date: Thu, 11 Dec 2014 10:58:39 +0000 [thread overview]
Message-ID: <20141211105839.GE30812@stefanha-thinkpad.redhat.com> (raw)
In-Reply-To: <1417613866-25890-6-git-send-email-mreitz@redhat.com>
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On Wed, Dec 03, 2014 at 02:37:25PM +0100, Max Reitz wrote:
> @@ -530,8 +530,16 @@ found:
> }
>
> /* XXX: cache several refcount block clusters ? */
> +/* In order to decrease refcounts, set @addend to the two's complement (giving a
> + * negative value and letting the implicit cast handle it is enough) and set
> + * @decrease to true. @decrease must be false if the refcount should be
> + * increased. */
The first time I read this patch I missed this quirk and thought that a
lot of places seemed to be doing the wrong thing with addend.
This is likely to cause confusion, why not make uint16_t addend truly
unsigned and leave the sign to bool decrease, as suggested by the
function prototype?
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next prev parent reply other threads:[~2014-12-11 10:59 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-03 13:37 [Qemu-devel] [PATCH v4 00/26] qcow2: Support refcount orders != 4 Max Reitz
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 01/26] qcow2: Add two new fields to BDRVQcowState Max Reitz
2014-12-03 14:51 ` Eric Blake
2014-12-10 15:08 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 02/26] qcow2: Add refcount_bits to format-specific info Max Reitz
2014-12-03 15:09 ` Eric Blake
2014-12-10 15:14 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 03/26] qcow2: Do not return new value after refcount update Max Reitz
2014-12-03 15:13 ` Eric Blake
2014-12-10 15:15 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 04/26] qcow2: Only return status from qcow2_get_refcount Max Reitz
2014-12-03 15:37 ` Eric Blake
2014-12-10 15:32 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 05/26] qcow2: Use unsigned addend for update_refcount() Max Reitz
2014-12-03 15:55 ` Eric Blake
2014-12-11 10:58 ` Stefan Hajnoczi [this message]
2014-12-11 11:03 ` Max Reitz
2014-12-12 11:07 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 06/26] qcow2: Use 64 bits for refcount values Max Reitz
2014-12-03 16:11 ` Eric Blake
2014-12-03 16:18 ` Max Reitz
2014-12-11 11:04 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 07/26] qcow2: Respect error in qcow2_alloc_bytes() Max Reitz
2014-12-03 17:12 ` Eric Blake
2014-12-11 11:10 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 08/26] qcow2: Refcount overflow and qcow2_alloc_bytes() Max Reitz
2014-12-03 17:41 ` Eric Blake
2014-12-11 11:12 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 09/26] qcow2: Helper for refcount array reallocation Max Reitz
2014-12-03 18:00 ` Eric Blake
2014-12-11 11:26 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 10/26] qcow2: Helper function for refcount modification Max Reitz
2014-12-03 18:48 ` Eric Blake
2014-12-11 13:36 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 11/26] qcow2: More helpers " Max Reitz
2014-12-03 19:17 ` Eric Blake
2014-12-11 13:40 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 12/26] qcow2: Open images with refcount order != 4 Max Reitz
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 13/26] qcow2: refcount_order parameter for qcow2_create2 Max Reitz
2014-12-03 19:29 ` Eric Blake
2014-12-11 13:41 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 14/26] qcow2: Use symbolic macros in qcow2_amend_options Max Reitz
2014-12-03 19:48 ` Eric Blake
2014-12-11 14:05 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 15/26] iotests: Prepare for refcount_bits option Max Reitz
2014-12-03 22:05 ` Eric Blake
2014-12-11 14:26 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 16/26] qcow2: Allow creation with refcount order != 4 Max Reitz
2014-12-03 23:02 ` Eric Blake
2014-12-11 14:41 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 17/26] progress: Allow regressing progress Max Reitz
2014-12-03 23:03 ` Eric Blake
2014-12-11 14:41 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 18/26] block: Add opaque value to the amend CB Max Reitz
2014-12-11 14:42 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 19/26] qcow2: Use error_report() in qcow2_amend_options() Max Reitz
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 20/26] qcow2: Use abort() instead of assert(false) Max Reitz
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 21/26] qcow2: Split upgrade/downgrade paths for amend Max Reitz
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 22/26] qcow2: Use intermediate helper CB " Max Reitz
2014-12-11 14:44 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 23/26] qcow2: Add function for refcount order amendment Max Reitz
2014-12-03 23:30 ` Eric Blake
2014-12-11 17:08 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 24/26] qcow2: Invoke refcount order amendment function Max Reitz
2014-12-03 23:35 ` Eric Blake
2014-12-11 14:46 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 25/26] qcow2: Point to amend function in check Max Reitz
2014-12-11 14:46 ` Stefan Hajnoczi
2014-12-03 13:37 ` [Qemu-devel] [PATCH v4 26/26] iotests: Add test for different refcount widths Max Reitz
2014-12-04 0:03 ` Eric Blake
2014-12-04 9:51 ` Max Reitz
2014-12-04 19:10 ` Eric Blake
2014-12-05 9:02 ` Max Reitz
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